SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f84e0d2df6db399ffb8fc43e3294dce187d43ce512f81b957b864be6543e4153' 
  AND token = 'fXxCf6OFrVH35rgX+La/KaCQMmKgv3FwkXDUH43WPgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}